The disclosure relates to a control device for controlling an electric motor, comprising a twist grip and a carrier on which the twist grip is rotatably mounted, wherein the twist grip can be brought into a first operating position by being turned from a neutral position in a first direction, and wherein the twist grip can be brought into a second operating position by being turned from the neutral position in a second direction opposed to the first direction.
Outboard motors for boats are often controlled by means of a tiller attached to the outboard motor. By means of a control device which is disposed on the tiller and comprises a twist grip, the motor can be accelerated and the propeller of the outboard motor can be set in rotation.
In outboard motors with combustion motors, the engagement of forward or reverse gears takes place by means of a selector switch for forward and reverse gears. The control device serves only to adjust speed, and can thus be turned in only one direction from the initial neutral position.
The control device is usually provided with a spring return mechanism, so that the throttle automatically returns to the idle setting when the boat driver releases the control device. For this purpose a simple return spring, which brings the twist grip back to the neutral position, is normally incorporated in the control device.
In the case of an outboard motor with an electric motor, the selector switch for forward and reverse gears can be dispensed with. The propeller's direction of rotation can be governed via the direction of the current. Thus in the case of an electric outboard motor the functions “direction of travel” and “speed” can be integrated in the control device. The direction in which the twist grip of the control device is turned governs the direction of travel, and the angle through which it is turned governs the speed. For reverse motion, the twist grip of the control device is simply turned in the opposite direction.
With an electric drive, it is again necessary for the twist grip of the control device to return to the neutral position when the boat driver releases the control device, irrespective of the direction in which the twist grip has been turned. The known spring return mechanism of control devices, as used in combustion motors, cannot be used in this case, since it acts in only one direction.
An object of the present invention is therefore to provide a control device with a twist grip that can be turned in both directions from an initial neutral position and is provided with an automatic return which, when the twist grip is released, turns the twist grip back to the neutral position.
The disclosure relates to a control device for controlling an electric motor. The control device comprises a twist grip and a carrier on which the twist grip is rotatably mounted. The twist grip can be turned in both directions from an initial neutral position, enabling the twist grip to be brought into a first operating position by being turned in a first direction, and into a second operating position by being turned in the opposite direction.
The disclosure further comprises an automatic return device. For this purpose a force element, a force transmission element and a deflection element are provided. The force element acts on the twist grip via the force transmission element and the deflection element, and applies a force to the twist grip. By this means the twist grip is turned back to the neutral position, irrespective of whether the twist grip is in the first operating position or the second operating position.
The term “force element” is to be understood as referring to an element that applies a return force for returning the twist grip. The force element can be designed as an electrical, magnetic, pneumatic, hydraulic or mechanical element. This means that the return force can be applied by electrical, magnetic, pneumatic, hydraulic or mechanical means.
In at least one embodiment, the force element is designed as a spring element which is elastically deformable. When subject to a force, the spring element deforms, and when the force exerted on it ceases the spring element returns to its original shape.
The force element is preferably elastically deformed by turning the twist grip of the control device, and hence by changing the rotation angle between the twist grip and the carrier. When the boat driver releases the twist grip, the force exerted on the force element ceases and the force element returns to its original shape. By this means the twist grip is turned, relative to the carrier, back to its neutral position.
In at least one embodiment, the force element is designed as a helical spring. The force element consists of a spring wire wound in a cylindrical, conical or barrel shape. The main direction of loading is along the longitudinal axis of the helical spring. In this case the helical spring can be designed as a tension spring or a compression spring. When loaded, i.e. when the twist grip is turned, the spring is either pulled apart or pressed together. The disclosure is not however restricted to helical springs. It is also possible to use other force elements, such as for example spiral springs.
A metallic force element or spring element is preferably used. It is however also entirely possible to use spring elements formed from another elastically deformable material, such as for example rubber springs.
The force transmission element serves to transmit to the twist grip the return force exerted by the force element, and turn the twist grip back to its neutral position. In at least one embodiment, the force transmission element is designed as a pull cable or linkage. Depending on the type of force element, either a force transmission element that transmits tensile forces or a force transmission element that transmits compressive forces is used. In this respect the combination of helical spring and pull cable has proved to be favorable.
The twist grip according to the invention must return automatically to the neutral position when it is released, irrespective of the direction in which it was turned. For this purpose, according to the invention a deflection element is used, which deflects the force transmission element such that it always acts on the force element in the same direction, independently of the direction in which the twist grip is turned. As deflection element, for example a roller, a sliding guide and/or a lever is used.
This is explained by means of an example. For the sake of example, a pull cable or pull wire is provided on the twist grip, and a deflection element is provided on the carrier. The pull cable or pull wire runs over the deflection element and connects the twist grip and a spring element which serves as a force element and which is attached to a fixed point on the carrier. When the twist grip is in the neutral position, the length of the pull cable or pull wire together with the spring element is at a minimum. When the twist grip is deflected relative to the carrier, the spring element is elongated. The defection element is arranged such that the spring element is always elongated in the same direction, irrespective of the direction in which the twist grip is turned. This means that when the twist grip is released, the direction in which the spring element recovers its original form, and thereby returns the twist grip to the neutral position, is always the same.
In at least one embodiment, two or more of the elements in the group comprising the force element, force transmission element and defection element are integrated in a single component. For example, in place of a spring as force element and a pull cable as force transmission element, it is possible to use a rubber cord which combines the functions of the force element and the force transmission element.
In at least one embodiment, the carrier is at least in part designed as a hollow body, and the force element is disposed in the interior of the carrier. This arrangement has the advantage that the force element, defection element and force transmission element are protected from external influences. This is particularly advantageous when the invention is used on a boat, since in this case the environmental influences are especially large. If the control device is for example used to control an outboard motor of a boat, the control device is exposed for example to water splashes, which can lead to corrosion and associated restrictions on functioning.
According at least one embodiment, the force element is attached on the outside of the carrier. This has the advantage that the return mechanism comprising the force element, force transmission element and defection element is easily accessible and easy to maintain.
At least one embodiment is advantageously used to control an electric motor that is part of an outboard drive for a boat.
A preferred area of application of the invention is electric outboard drives, wherein the electric motor drives a propeller. In this case the control device serves to regulate the speed and select the direction of travel. For forward and reverse travel, the twist grip can be turned in different directions from the initial neutral position. The first and second operating positions thereby designate forwards and reverse travel respectively.
The invention and further aspects of the invention are explained below in greater detail using the schematic drawings. Other features and advantages will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the presently described embodiments.